Switch and signal control system for railroads



March 2, 1954 JUDGE 2,671,164

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed Sept. 8, 1949 12 Shee'ts-Sheet 1 F lehl.

23M. 35ML 45ML 2AM ZBY a'N 5'12 1N VEN TOR.

BY i -W '4 ATTORNEY T. J. JUDGE SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed Sept. 8, 1949 12 sheets-sheets IO XR 11?]? 12102 ZAY EAN FIG.3A.

TTORNEY March 2, 1954 T. J. JUDGE TCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS SWI 12 Sheets-Skies: 4

Filed Sept. 8, 1949 INVENTOR.

W M. m fig ATTORNEY glL' w March 2, 1954 T. J. JUDGE 967141 SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed Sept. 8, 1949 12 Sheets5hoe'c 5 11cm 0140!: 11m 552 g l 146 m m I144 145 may 1] 1113c 2% w z. w :2 mm? m (9 11M? W I -r- *7 1 120 1 I FIG. 13.

ARRANGEMENT OF DRAWINGS F|6.2A. F1625. FlaA 565A. 56.55. F16.5C FlaD. F167.

if INVENTOR. BY 2 j i ATTORNEY March 2, 1954 J. JUDGE 2,671,164

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed Sept. 8, 1949 12 Sheets-Sheet 6 I INVENTOR. (H E815 7 I MM, I

@ATTORNEY T0 FIELD STATION 7 IICH T. J. J UDGE 2,671,164

12 Sheets-Sheet 7 SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Filed Sept. 8, 1949 IINB 55 L HNR March 2, 1954 3nveutor A Gttorneg March 2, 1954 JUDGE 2,671,164

SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS I Filed Sept. 8,-1949 1'2 Sheets-Sheet a 165 265 ads as sea as ms 5 5 sea cs (H e? ifiHHHHHHQ 1 T as l I 209 I l w- I I Pi-Up I [T I 1 l 10: I I I m' 0 24a 7 INVENTOR.

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2 T1 zsn E m ATTORNEY T. J. JUDGE March 2, 1954 SWITCH AND SIGNAL CONTROL SYSTEM FOR RAI LRoAbs Filed Sept. 8, 1949 JNVENTOR. W a; BY

4z;/ ATTORNEY T. J. .IJUDGE SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS March 2, 1954 Filed Sept. 8, 1949 will l| N 5 T1 R E ELL m m m m C W% wm m mmm NTN. Haw

Patented Mar. 2, 1954 SWITCH AND SIGNAL CONTROL SYSTEM FOR RAILROADS Thomas J. Judge, General Railway Madrid, Spain, assignor to Signal Company, Rochester,

Application September 8, 1949, Serial No. 114,662

This invention relates to switch and signal control systems for railroads and it more particularly pertains to such systems of the type where routes are automatically established in response to the manual designation of their respective entrance and exit ends.

This invention is to be considered as providing improvements in an entrance-exit switch and signal control system of the general type disclosed in my prior Patent No. 2,298,946, dated October 13, 1942. The nature of the system according to my prior patent and according to the present invention is to provide for the establishment of routes in response to entrance-exit designation in complex track layouts by the selective energization of switch position selecting relays provided for each of the respective crossovers and single track switches of the track layout, there being a definite number of relays required for each of the single track switches and crossovers, irrespective of the number of difierent routes thereover that may be established. The designation of the respective entrance and exit ends of the routes is accomplished by manual actuation of buttons which are preferably disposed on a track diagram at positions comparable to the respective entrance and exit points. The buttons may, however, be otherwise disposed as on a keyboard as disclosed in the prior application of N. D. Preston Ser. No. 791,371, filed December 12, 1947, now Pat. No. 2,649,536, dated August 18, 1953. Indications as to the routes that have been established and the conditions of the track switches are provided on the track diagram by the selective energization of indicator lamps and switch position indication means which may establish a substantially continuous line of light corresponding to each route according to the provisions of my above mentioned prior patent. In response to the energization of the switch position selecting relays, switch control relays are energized which in turn control the actuation of the respective switch machines of the associated crossovers and single track switches.

' An. object of the present invention is to check the response of the respective switch control relays to their respective switch position selecting relays as the respective routes are selected in response to manual designation.

Another object of the present invention is to render the selection of positions for the respective track switches effective for each route designated for one single track switch or crossover at a time, taken in sequence, starting from the exit end of the route, such selection. being per- 19 Claims. (Cl. 246134) 2 mitted to progress only provided that the switch control relays and the switch position selecting relays for each track switch are actuated in correspondence.

Another object of the present invention is to permit the execution of a control for clearing a signal governing entrance to a route, only pro vided that the switch position selecting relays and the associated switch control relays for each single track switch and each crossover in that route have been correspondingly conditioned.

Another object of the present invention is to transmit by code communication to a remote track layout switch and signal controls for each route having its entrance and exit ends designated at a control oifice, such switch controls being transmitted only provided that the switch control relays for the respective associated track switches in that route have been checked as being positioned in correspondence with the switch position selecting relays which are automatically conditioned in response to entrance-exit designation. The transmission of a signal control is dependent upon the checking of correspondence between the switch control relays and switch position selecting relays for all track switches included in a route that is designated.

Another object of the present invention is to transmit by code communication switch controls for the respective track switches of a designated route, only provided that a change is required to be made in the position of that track switch for alignment of that route. This is accomplished by maintaining the switch control relays at the control oilice in their last actuated positions, and unless there is a change in their positions required for a new route having its entrance and exit ends designated, there is no automatic start of the communication system for the transmission of a switch control for that track switch.

Another object of the present invention is to permit the clearing of a signal for governing entrance to a route in response to a signal control communicated during a cycle of operation of the code communication system, only provided that each switch control that has been communicated during the last preceding cycle of operation has been effective to actuate a field switch control relay in correspondence with the particular switch control code that has been received in the field.

Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawings, and in part pointed out as the description of themvention progreses.

In describing the invention in detail, reference .designation for.

will be made to the accompanying drawings in which like reference characters designate corresponding parts throughout the several illustrations, in which those parts having similar features and functions are designated by like letter reference characters which are generally made distinctive by reason of preceding numerals representative of various switch and signal locations, and in which:

Fig. 1 illustrates a miniature track diagram having entrance and exit buttons disposed thereon for designation of the respective entrance and exit ends of routes to be established;

Figs. 2A and 213 when placedsideby side illustrate an initiating circuit network for use in the selection of the positions of track switches. in response to entrance-exit designation;

Figs. 3A, 3B, 3C and 3D when placed side by side illustrate a completion circuit network for switchposition selection and switch control together with code communication means for.com-

rmunieating. switch. and signal controls when they have been selected in response to entrance-exit routes to be established;

vFig. illustrates a typical means .for control ..0f,an;entrance. control relayin response to. the

-manual.actuation. of; an. entrance .controlbuttcn; Fig. 5 illustrates. another typical meansior the control otanentrance relay in response to .en-

trance designation which is. particularly adapted ior-usewhere call-on signals. are employed; I Figs. fiAvandfiBwhen placedside by sideillus- .trate. a means for...executing respective: switch .and :signal controls .at a .field. station in. response -.to.the transmission by code of such. controls from a. control ofiice;

Fig. 1. .illustrates ameans for thecontrolrof .signalsin the held. in-accordance with switch andssignal; controls v that ar communicated .to the field from the control omce;

. Fig. 8. illustrates-the track layout for which 4 the system. is assumed. to. be provided 'for .the .embodimentherein disclosed,-together with typical circuits relative to-thepower operation-of vthe track switches;

Fig. 9 illustrates the controloi therespective .signal. -unitsand signal repeater :relays for a ,typical. signaladapted for providing either .high signal or call'on indications;

. Fig. v10 .illustrates the control of atypicabsig- ,nal. with'its repeater .relays where call-on controls are not employed ---Fig. 11 illustrates a systemfor the-communication .of indications from the field-to the control 011366; -Fig. ;l2-is a-code chart showing the useof re- -spective code characters from the communicationof switch and signal controls required for the establishment of any selected. route through the track layout illustrated inFig. 8; and

Fig. 13 .shows the. relation-betweencertain sheets ofthe drawings.

.The embodimentchosenior the disclosureof the; present... invention ..has.. beenflparticularly adapted. to...show typical. conditions. to. benchcountered practice for the .purposeotillustra-ting principles. involved. that may .be applied to .morecomplex track. layouts rather. than attemPtingtuillustrate the scope. of the present invention. Schema-tic. circuit diagramshave-been used in the; conventional manner, rather than attempting .-.to illustrate the actual construction and arrangement of parts, i that wouldbevemployed in practice. The symbols (1+) :and-(-) are-i'cmployed' to indicate: the positiveand nega- 1 (SL) are used to. indicate 'co de characters transmitted over the: communicationsystem, each character comprising a combination of a long .end a short period, the symbol (LS) represent-- ing. a code character having long and short periods respectively, and the symbols (SL) representing a code character having respectively short and longrperiods.

closed-r forexample, in the patent halal-2A- and a call-on signal With reference. to Fig. 8, the track layout chosen for thisembodiment of the present in- .ventioncomprises two parallel tracks interconnected by crossovers 2 and i, and a third track connected by the single track switch 3 to the upper of the two main tracks as illustrated in Fig; 8.

Signals oi the searchlight type such as-is disto O. S..,Field No. 2239316,; dated April22, 194i, are illustrated .,as being located at -pointsscomparable.to the rei spective entrancerand exitends of routes which may-be established throughathe track layout.

'Signa'ls i0, H and-.42- are provided for governing entrance to the track layout by eastbound trains, signal 12 being illustr-ated:-ashaving a'high sig- IZB. The signals l4 and 15 are'proyided for governing entrance to the respectiveroutes oft the trackelayoutfor. west bcundetraffid 'Thewsignal iiis a signal for governing eastboimd-trafficlocated at an interoithe twozmain tracks asillustrated in Fig.- Exit fromthe-traclcdayout-is governed by the -signals-l5;i1;=l8,:l9 and- 20.

layout in the lower ediate point-.iir the :track Although the signals illustrated are of-:thesearcldight type, it is to beun'derstood'rthat' other types-or" signal such as semip'hore, :posilight, or 1 light. signals having individual:colorslamp units can be used-in accordance with :therequirements ofpractice.

FOrLthisembodimentof the present invention, it hasbeenassumed: that the track layout is 10- .catedfremotel'from arncontrol. tower, or control 'ofiice;.;and that a-icode communication system is employediior the communication of controls and indications betweenthe'control 'oiiice and the track layout. It'fis also. assumed, that the code communication'systememployed is of the character disclosed, :for example, in the-patent to Vf.-'D;:.Hai1es etlal.,uPatent'No.' 2,399,734, dated May 1, 1946,:but itiSl'tOfbBllIldBlStOOd that other suitable-"types:ofxcodetcommunication systems may-beemployed inaccordance with the requirerne'nts ot =practice. lThus. torsimplification of the presentcisclosure, details incident to the code communication system as disclosed in that patent need-not be=consiclered, as reference can bernade-to the-l-l'ailes et al'.-patent for a disclosure ofthese'details. "For the purpose of facilitating 'reference'to the Hailes 'etal. patent, the apparatus employed in. this embodiment of the present invention corresponding to apparatus shown in that patent. is'identified by corresponding letter. reference characters. In. addition to change relays CI-Ildisclosed in the Hailes et a1. patentasbeing:usedin the initiation of the system,-..-relays ACTrL-are associated with certain of the change .relays =CH-' at. the...contro1 office. .for purposes relative-to 'the-..-initiation.ot the. system for theitransmissionnf. :switch controls from the controlsicfiicestm theitraclralayoutcinz a manner .which will be more readily understoodwhen con sidering the mode of operation of the system.

The relays LS and SL, as in the Hailes et al. patent are code determining relays which actually determine by their selective energization as to whether the code characters transmitted during a cycle of operation are respectively (LS) or (SL) characters. It is thus provided that the relays LS and SL are selectively energized during respective control cycles to transmit the control codes formed in accordance with the code chart of Fig. 12.

The designation of routes to be established is made by the actuation of respective entrance and exit control push buttons on a suitable control machine in the control office. The control machine has a control panel upon which is constructed a miniature track diagram (see Fig. 1) provided for the track layout (see Fig. 8). The construction of the track diagram is principally by translucent inserts where line of light indications are provided, the energization of the indicator lamps for the illumination of these inserts being provided in any suitable manner such, for example, as is disclosed in my above mentioned prior patent.

Entrance buttons NE and exit XB are provided on the diagram at points comparable to the ends of the routes as defined by the location of the signals in the track layout.

Each of the entrance buttons NB is of a push pull type being biased to a normal position from which it can either be depressed or pulled out. The depression of the button is used for designation of that entrance point for a route to be established, and the pulling out of the button is used for designation of restoration for a route having an entrance point at the associated signal location. As a means for designating a low speed call-on signal as distinguished from a high speed signal for a given signal location, it is provided that the entrance button NB for that location can be rotated to a distinctive operating position for designation of such call-on signal control. Therefore the button l2NB can be rotated in a counter-clockwise direction for designation of the call-on signal 23 at the associated entrance point. It is also provided that the rotation, of the entrance button IZNB in the opposite direction from its normal position can be used to designate the entrance end for a route to be governed by a non-stick signal. Conditions incident to the actuation of the entrance button IZNB will be hereinafter considered in detail with respect to these distinctive positions as being typical of an organization that could be provided for other entrance points of the track layout in accordance with the requirements of practice. The structure of a control button to provide such distinctive operating positions can be provided, for example, as is shown in the prior patent to J. F. Merkel, Patent No.

2,305,185, dated December 15, 1942.

Each of the exit buttons X3 is of the selfrestoring type having a contact associated therewith which is closed only when such button is depressed from its normal biased position.

Although separate buttons are provided for designation of the respective entrance and exit points for each of the route ends, it is to be understood that the contacts of such buttons can be combined in a single button having the required number of distinctive positions, and that a single button can be used for each of the route ends if circuit means is provided aslocked conditions of the track conditions of the signals.

sociated therewith for supplying the distinctive conditions of entrance and exitv designation, dependent, for example, upon the sequence of operation of the control buttons for the designation of the respective entrance and exit ends of the respective routes desired to be established.

An auxiliary switch control lever SML is pro vided on the control panel for each of the crossovers and each of the single track switches in order to facilitate the operation of the track switches to free them of obstructions such as snow and ice, and to provide an auxiliary means for the establishment of routes through the track layout. Each of the auxiliary switch control levers SML has a normal center position and two operating positions, one for operation of the associated track switch or track switches to normal positions, and the other for operation of suchtrack switch or track switches to reverse positions.

Respective entrance relays NR and exit relays XR are provided for the entrance and exit buttons. These relays are responsive to the actuation of the associated buttons when the entrance and exit ends of routes to be established are designated. Each of the entrance relays NR is provided with stick circuit energization so that it can be maintained picked up for stick signal control dependent upon the entrance of a train into a route emanating from that en trance point. Where a call-on signal is provided, another entrance relay CNR is provided as illustrated in Fig. 5 in addition to the regular entrance relay NR for that particular entrance point.

The automatic selection or" the positions of the track switches for the respective routes having their ends designated comprises the use of relays Y, AY, BY (see Figs. 2A and 215), N, AN, BN and R (see Figs. 3A and 3B). The relays Y, AY and BY are conditioned in response to entrance designation, while the other relays are selectively energized in response to exit designation, and their energization selects the positions of the respective track switches that are required to establish a route entrance and exit points.

Switch control relays NWZ and. RWZ are employed in providing more direct control for the respective track switches, and where the track layout is remote from the control office, as is assumed in this embodiment of the present inbetween designated .vention, these relays are used to select switch control code characters for transmission over the code communication system to the remote track layout. The controls for the relays NWZ and RWZ diiTer from their associated relays N,

to the last position called for the associated track switch. Thus these relays are not restored to a deenergized position upon passage of a train or upon cancellation of a route, but are rather maintained picked up by their stick circuits until the opposite position of the associated single track switch or crossover is called for by the associated switch position selecting relays N, AN, BN and R.

Various magnetic stick relays are provided at the control ofiice for receiving indications coromunicated from the field as to the conditions of occupancy of the respectivetraci: sections, the

switches, and the There is "also -a magnetic stick relay WCKR provided at the control bmce whichi is conditioned over the code 1 communication' system to-indicate a condition where a switch controlrelay in the-field fails to respond to acode which has been received in the field for its control.

'In addition to theprovisionof code receiving means inthefield as disclosed in the above mentioned Haileset al; patent, an organization of decoding relays is provided as illustrated in Fig. 6A comprising the relays CS which ar selectively responsive for the respective channels of the code communication system during'each control cycle of operation, and in accordance with the selective energization of these relays during a cycle, switch and signal control application relays are conditioned during an execution period at the endof thecycle. Because there are a greater number of controls to be communicated than can be scanned during a single cycle of communication, the respective controls are grouped in stations and station relays ST are provided in the field for identifyingthe particular group of relays for which controls are intended during any particular cycle of operation.

Switch control application relays WN and WE. are provided in the field (see Fig. 6B) for the respective single track switches and crossovers, and these relays are conditioned in response to the respective switch control codes that are received. Similarly, a relay G2 is provided for each signal as an application-signal control relay governed by the reception of signal control codes communicated from the control oiiice. A relay B isprovlded for use in connection with the restoration of the signals to stop restoration codes communicated from the control ofiice.

Relays G are provided for more directly governing theenergization of the signals, such relays being conditioned by the application relays GZ, and being permitted to be energized only subsequent to the complete alignment of a route extending between entrance and exit points that have been designated. The check of the complete operation of the track switches in the alignment of the routes is accomplished by normal and reverse correspondence relays NCR and RCR respectively for each crossover and each single track switchin accordance with the usual practice.

Lock relays L, route locking relays ES and WS, and track relays TR are provided as associated with the respective track sections in a manner well known to those skilled in the art, and, for simplification of the present invention, the detail controls of these relays have not been shown. The manner of control of lock relays L and route locking relays ES and WS which is typical of that which could be provided for use with the system according to the present invention is disclosed in my above mentioned prior patent.

Having thus considered the general organization of the apparatus provided for this embodiment of the present invention, it is believed that the details of the circuit organization may be more readily understood when considering typical operating conditions of the system which may be encountered in practice.

Operation Normal conditions-For the purpose of facilitating the description, of the present invention, the conditions wherethfelast routes establish through the track. layout required the trackswitches to be in their normal positions will be in accordance with denim con'sidered'as the normal conditions of the system. It will also be assumed that under normal conditions there are no routes designated for establishment; the'signals are all at stop, the communication system is at rest, and there are no controls or indications stored for communication by the communication system.

Under these conditions the switch control relays NWZ (see Figs. 3A and 3B) for the respective crossovers and the single track switch are energized by their stick circuits. Thus the relay ZNWZ, for example, is energized by its stick circuit extending through its front contact 30 and through back contact 3| of relay ZRWZ.

In accordance with there having been no changes in the conditions of the relays WZ at the control oifice subsequent to the last switch controls that have been transmitted to the field, the relays 2-3ACH and AACH (see Fig, 3D) are normally maintained energized by their stick circuits. The stick circuit for relay 2--3ACH extends through back contact 3?. of relay ZRWZ, back contact 33 of relay tRWZ and front contact 34* of relay 2-3ACH. The relay EACH which is associated with the crossover 4 is maintained picked up by its stick circuit through back contact 35 of relay GRWZ and its front contact 35.

At the track layout in the field, the relays WN (see Fig; 6B) for the respective crossovers and the single track switch are maintained picked up by stick circuits such as the stick circuit for relay ZWN which includes front contact 3'! of that relay and back contact 28 of relay ZWR.

The relays 2-3WC and 4WC (see Fig. 6A) are normally maintained picked up in accordance with the last switch control codes transmitted having been efiective to correspondingly actuate the associated switch control relays. Relay lWC is maintained picked up normally by a stick circuit including its front contact 33 and back contact id of relay 2ST. Relay 2-3WC is normally maintained picked up through its stick circuit including its front contact ll and back contact 42 of the station relay IST. The correspondence repeater relay WCP is normally energized in accordance with the energization of the relays 2-3WC and dWC by a circuit comprising contacts t3 and 44 of relays 2-3WC and 4W0 respectively.

The correspondence relays NCR for the respective crossovers and the single track switch are normally energized. The circuit for the relay BNCR which is associated with crossover d is illustrated in Fig. 8 as including suitable selections by the point detector contactor mechanisms of the switch machines'associated with crossover 4 and front contact d6 of relay iWN. This circuit is to be considered typical of the circuits that can be provided for the relays NCR that are associated with other track switches.

The red repeater relays RGP associated with the respective signals are normally energized in accordance with their associated signals being at stop. The relay HRGP for signal l l, for example (see Fig. 10), is normally energized through contacts t9 and 59 of the signal mechanism, and the relay l2RGP of signal l2 which is associated with both units A and B of that signal is normally energized through the contacts 5! and 52 of signal unit HA and the contacts 53 and 54 of signal unitlZB. v

selection of switch positions- 111, response to manual designation of an entrance. p n y the actuationof a button NB-for a route to be established, energy is applied to a circuit network, conveniently called an initiating circuit network, for the selective energization of the relays Y, AY and BY and for conditioning the exit relays XR so that they can be energized upon designation of the corres onding exit points, provided that there is an available route extending from a prior designated entrance point to the exit point designated. There is actually a separate initiating circuit network for each direction of tranic, each network having circuit branches corresponding to all possible routes emanating from any entrance point that may be designated for that direction of traffic.

If it is assumed that it is desirable to set up a route for an eastbound train having an entrance point at signal I I, the entrance button IINB (see Fig. 1) is actuated to its depressed position, and such actuation according to Fig. 4 provides for the energization of the entrance relay NR. This relay is maintained picked up by its stick circuit which includes a normally closed contact '55 of the entrance button IINB, front contact 56 of the track indication relay STK, and front contact 51 of relay IINR. Thus the relay I INR is maintained picked up until it is released in accordance with the reception of an indication that the track section 3T (see Fig. s) has become occupied because of a train accepting the signal I I. Restoration can also be made manually by pulling out the button I INB i from its normal position and thus opening the stick circuit for relay IINR at contact 55 of the button IINB.

Upon the picking up of relay HNR, energy is applied to the initiating circuit network by front contact 53 (see Fig. 2A) and energy applied by this contact is fed through the initiating circuit network that is provided for the setting up of routes for eastbound traffic so that it feeds through a branch of the network corresponding to each available route that is emanating from the signal II. Thus, assuming that the normal conditions of the system prevail at a time when the entrance button II NB is actuated, there are three possible routes available emanating from signal I I, one route being from signal I I to signal l6, another route being from signal II to signal l3, and a third route being from signal II to signal I7 via crossover 4. When this route via crossover 4 is not available, and a route is available from signal I I to signal I! via crossover 2, the route via crossover 2 can be set up by endto-end operation without requiring entrance and exit designation for signal !3.

The relay iBY (see Fig. 2B) is energized in response to application of energy to the initiating network by front contact 58 (see Fig. 2A) of relay llNR. The circuit for the energization of relay ABY extends from including front contact 58 of relay IINR, back contact 59 of relay IIXR, back contact 60 of relay 2R, back contact EI of relay 3R, back contact 52 of relay 3Y, wire 63, back contact 56 of relay dAN, back contact 65 of relay GEN, and winding of relay 4BY, to The relay 3Y is not energized at this time because it is energized only by energy feeding from front contact 66 of relay IONR, and the relay ZBY is not energized because that relay is energized in accordance with the designation of signal I2 as an entrance point v If it is assumed that from signal II to signal is actuated subsequent entrance button IINB, and-the actuation of this button is effective to pick up the relay ISXR, by

H, the exit button I5XB for routes to be established. the route isto be set up to the actuation of the relay lBY. The circuit for the the energization of a circuit extending from including front contact 58 of relay IINR, back contact 59 of relay IIXR, back contact 60 of relay 2R, back contact tact B2 of relay 31, wire 83, back contact 64 of relay 4AN, back contact 65 of relay 4BN, front contact 6'1 of relay 4BY, winding of relay I5XR, back contact 63 of relay HENR, back contact 69 of relay I 5GK, and button IEXPB in its depressed position, to This relay when picked up establishes a stick circuit at frontcontact I0 to maintain the relay picked up subsequent to the restoration of the button I5XPB to its normal position.

Similarly, other two routes emanating from signal II were to be designated, the corresponding exit relay XR would be picked up and maintained picked up by a stick circuit so that its energization would be dependent upon energy feeding through the circuit network from the front contact 58 of the entrance relay IINR.

In response to the picking up of the exit relay ISXR for a route extending from signal I I to signal l'i' under the conditions above considered, a pick-up circuit is closed in the completion circuit network (see Figs. 3A and 8B) for the relay 4R as selected by the energized condition of the energization of relay 4R extends from including front contact H of relay I5XR, front contact I2 of relay iBY, and winding of relay 4R, to

Relay 4R. when picked up closes a pick-up circuit for the switch control relay 4RWZ which is also associated with the control of the track switches of the crossover 4. This circuit extends from including front contact 13 of relay GLK, front contact 74 of relay BLK, front contact :5 of relay SR, and upper winding of relay 4RWZ o of the relay IRWZ by this circuit checks that the lock indication relays lLK and BLK, which are provided for the detector track sections at the" respective ends of the crossover 4 are in their picked up positions corresponding to the energization of corresponding lock relays at the track layout.

3Y, and winding of relay 3N, to

6| of relay 3R, back conif the exit point for either of the It will be noted that the energization.

relay 3NWZ is alreadypickedup atthis time, but the picking up of relay 3 Ncloses a pick-up circuit for this relay so that it could be picked up if it were in its dropped away position at a time when the normal position ofthe track switch 3 were called for. This pick up circuit extends from including front contact lil of the lock indication relay -liLK, wire 82; front contact 83 of relay 3N, and upper winding of relay BNWZ, to

With relay SNWZ picked up, picked up, a circuit is closed through the coinpetion circuit network for the picking up of the relayjAN to select the normal positions of the track switches of the crossover 2. This circuit extends from including front contact ii of relay Dim, iront contact 12 of relay iBY, front-contact 18 of relay ARWZ, front contact lli otrelay 4B,, wire 86, back contact ill of relay 3, front contact as of relay 3NWZ, front contact 8 ;of relay 3N, and winding of relay ZAN, to e relay, 2AN in picking up establishes a pickup circuit for the relay ZNWZ, although the relay;2NWZ is already in its picked up position at -this timeunder the assumed conditions of operation The pick-up circuit for the relay ZNWZ extends from including front contract 86; oi the lock indication relay Lilli, front contact 810i relay TLK, front contact 88 of relay 2 A N,- and upper winding of relay ZNWZ, to l iii onthe other handan operator were to actuatethe exit button ISXB subsequent to the designation of an entrance point at signal H, rather than the button ISXB, a route would be auton atically selected over the crossover 2 to signal l 3-.; This is because the relay EBY is deenergiaed at that time, and with that relay in its deenerg-ized position, the energization of the relay 23 in .the completion circuit network is selected. The relay 2B, is energized under these conditions by-Ya circuit extending from including front contact '89 (see Fig. 3B) of relay i-(iXR, v'ire so, back-contact 9! of relay QB'Y, and winding of relay: 2R, to RelayER upon picking up under these conditions would provide for the energization of relay Z-RWZ by the closure of a circuit including front of relays ELK, *ILK and 2B respectively.

. rue general nature ofthe route selection means is-such that if the route extending from signal Hsto signal entrance-exit designation via crossover l, it can befautomatically selected via crossover 2 by endtJ-ehd entrance-exit designation without requir ingientr ance and exit designation for signal is.

,To" consider the specific circuits involved in this'mode of operation, it will be assumed that are crossover G is locked in its normal position as by -a'r'oute extending and relay 31d from signal iii to signal it so as to select that a route will be established from signal H to signal ll via crossover 2 in respouse to the actuation respectively or" the buttons llNB and iEXB. Because of the relay can being picked up at this time, the circuit that has been'desc'ribed for the energization of the relay d BY is open at back contact es (see Fig. 2B) and thus the relay 4BY remains deenergized subse- (merit to the actuation of the entrance button NB. This opens the circuit feed for the relay lSXR through the portion of the initiating circuit network comparable'to the crossover i.

The through route control entrance repeater relay ISNP is energized through the initiating circuit network in a circuit extending from including front contact 58 (see FigGA) of relay HER, back contact iifiof relay HXR, back concontacts 85, El, and 52' I! is not availableat the time of its '1 tact 93 0f relay ZAN, back contact 9 of relay ZBN, back contact 95 of relay ZTBY, wire 9t, back contact 91 of relay I3XR, back contact 98 of relay I3GK, front contact 99 of relay RiLK, back contact 108 of relay IENR, and winding of relay ILNP, to (-L Relay l3NP when picked up establishes a stick circuit through its front con tact wt to shunt the back contact iilii of relay IBNR out of the circuit just described. Relay i3NP when picked up conditions a circuit so that the exit relay IEXR can be energized when the exit button .IEXPB is actuated. The circuit energized for relay IEXR under these conditions extends from (-5-), including front contact it? of relay ISNP, back contact i633 of relay 5R, back contact Elof relay ABY, winding of relay ESXR, back contact 58 of relay iENR, back contact-S8 of relay iEGK, and button iiiXPB, to The picking up of relay 15KB under these conditions establishes a stick circuit at front contact 'iii to maintain that relay picked up subsequent to the restoration of the exit button IEXPB from its depressed position.

Upon the picking up of these conditions, a circuit is closed for the relay ZEN including front contact H (see Fig. 3B) of relay i5XR, and back contact '52 of relay iBY. When relay 4BN is picked up by the energize-- tion of this circuit, the normal switch control relay iNWZ is energized by .a circuit including front contacts 53, i l, and Hi l of relays QLK, ELK and ABN respectively.

When the relay QNWZ has become picked up, theentrance relay i3N'R, for the entrance point at signal 93 has its lower winding energized in the completion circuit network by a circuit extending from (-1-), including front contact ll of relay iEiXR, back contact .12 of relay lBY, front contact N5 of relay GEN, front contact lfifi of relay ANWZ, front contact it? of relay I3NP, and lower winding of relay lSNR, to

Upon the picking up of relay iBNR, the relay IEXR becomes picked up by its energization in the initiating circuit network through a circuit including-front contact 58 (see Fig. 2A) of relay HNR, back contact 59 of relay HXR, back contacts 83, $4 and 95 of relays respectively, wire 96, winding of relay 13KB, and front contacts I08 and H39 of relays 13NR and l-ENP respectivly. This-relay when picked up closes a stick circuit at front contact H0 to provide that the relay is maintained energized dependent upon energy feeding from the front contact 58 of relay i'iNR, even though the relay lBNP is dropped away by the opening of its circuit at back contact 91 of relay liiXR. It will be noted that the relay iBNR is maintained picked lip, however, by the energization of a stick circuit'for its upper winding which can be comparable to the stick circuit that has been described for the relay 1 INR (see 'Fig. 4).

The picking up of relay ISXR, under these conditions energizes the relay 2B for selecting the reverse positions of the track switches of crossover 2 in a manner which has been described, and the picking up of that relay provides for the energization of the-switch control relay ERWZ.

Having thus considered specifically the selection of typical routes through the track layout and the conditioning of the switch control relays NWZ and RWZ in accordance therewith, it is believed that it should be readily understood that a similar mode of operation is efiective in the establishment of other routes which may be relay ESXR under desired-to beesmbiisneg either in the present ZAN, ZEN and ZBY track layout or in other track layouts to be encountered in practice. It will be noted from the typical conditions that have been considered that the switch position selecting relays AN, BN, N and R for the respective crossovers and single track switches are energized in cascade, starting with the relays associated with the track switch of crossover adjoining the exit end of the route, the cascade energization of these relays being effective progressively only so long as the associated relays NWZ and RWZ are positioned in correspondence with the respective normal and reverse positions of selected.

Transmission of control codcs.As reference can be made to the above mentioned Hailes et al. patent for details relative to the operation of the code communication system, it is suihcient for an understanding of the present invention to assume that the code communication apparatus has a general mode of operation for the communication of controls wherein controls are transmitted during respective control cycles of operation which are initiated from a period of rest of the system.

The first three code characters transmitted according to the present embodiment are conveniently called station selection code characters, and although they do not select respective spaced stations along the railway as is done in centralized traffic control systems, they select the energization of respective station relays ST at the track layout, and the selective energization of these relays ST identifies the particular function or functions that are to be controlled during that control cycle.

It is therefore provided, according to the code chart of Fig. 12, that distinctive station selection codes are assigned respectively for the control of signals l9 and M, signal ll, signal [2, signals 13 and I5, switches 2 and 3, and switch 4.

The last two characters transmitted during a control cycle define the specific control that is to be applied to the particular device that is identified by the first three characters transmitted during that cycle. Thus, for example, if the cycle is for the control of a particular one of two opposing signals, the transmission of an (LS) character as the fourth character of the cycle and an (SL) character as the fifth character of a cycle establishes that the signal is to be cleared for governing traffic to the right (eastbound traffic). It is therefore provided, for example, that if the station selection code is for signals and hi which are opposing signals, the transmission of the characters (LS) and (SL) as the respective fourth and fifth characters of the control cycle selects that the signal I0 is to be cleared for governing eastbound trafiic. If the same station is called and the fourth and fifth characters are respectively (SL) and (LS), it is selected that signal I4 is to be cleared for governing traflic to the left (westbound traffic). If a signal is to be put to stop, the fourth and fifth characters are both (SL) characters, and if the signal control communicated is for a callon signal, both the fourth and fifth characters are (LS) characters. 7

If a switch station is identified by the station portion of a control cycle, the remaining characters are used for identifying the position to which respective track switches are to be operated, an (LS) character being used for the operation of the track switch to its normal position, and an (S-L) character being used for operating a track switch to its reversed position. Inasmuch the track switches that are cation of a switch control, as many switches-canbe controlled by a single cycle of operation as there are number of channels provided in the communication system above that which is required for station selection. For this embodiment of the present invention two channels have been provided in addition to the station selection channels, but additional steps may be employed in the communication system for expansion of both station selection and control codes in accordance with the requirements of practice. According to the general mode of operation of the communication system disclosed in the Hailes et al. patent, a start relay CH is picked up at the control office for initiating transmission to a designated field station, and this relay when picking up causes the picking up of an associated relay LC which has a number of contacts associated therewith which connect code determining and switch jumper contacts to the respective channel wiresof the code communication system for selecting the characters to be transmitted during a control cycle that has been thus initiated. These relays LC are energized in a chain circuit network so that it is determined that control cycles are transmitted for respective stations in a predetermined order under conditions where controls for more than one station are designated for transmission contemporaneously. v V

Similarly in this embodiment of the present invention, start relays CH are provided for the respective stations, and these relays are picked up for their stations in accordance with the selection of a route by the entrance-exit. selecting network. This is true for the communication of the switch controls as well as for the communication of the signal controls. In either case, in the establishment of routes, it is required that a route selection be completed before there is any initiation of the system into a cycle of operation for the communication of one or more switch controls to the remote track layout. I

In accordance with principles of operation set forth in the above mentioned Hailes et al. patent, a relay LCS is picked up upon initiation of a cycle of operation for transmission to any one of the stations, and the picking up of this relay prevents the picking up of any other relays LC until that cycle of operation has been completed. To consider a specific example of the selection and transmission of switch and signal control codes in response to entrance-exit designation, it will be assumed that a route has been designated extending from signal H to signal [1, and that the route has been selected via crossover i so as to cause the relays ZNWZ, 3NWZ and HRWZ to b picked up in a manner which has been described.

In accordance with the 4RWZ, which is effective prior to thedropping away of the relay lNWZ, the stick circuit for the normally energized change relay 4ACH (see Fig. 3D) is momentarily openbecause of'contacts H l and 35 of relays 4NWZ and ARWZ being both open at the same time momentarily so that the relay 4ACI-I becomes dropped away. The dropping away of this relay, by the closure of its back contact H2 conditions a circuit for the lower winding of relay 4CH so that such relay can be picked up to initiate the transmission of a control cycle for the control of the track switches of crossover 4 upon the route selection being completed and the actuation of the switch picking up of the relay a encies.

control relays-NW2- and-Rwzbeing checked ion relayJlAGI-I..includingback-contacts 421 I22 the respectivetrack switches-of .tharoutgn and l23.of relays SB, CF and dlcs respectively,

Becauseof there being-no change-called for front contact. l24- of. relay GC-H and front-con in the positions of the trackswitches ot'cross tact 129 ofrelayfiCI-I. This circuit isonly mo-: over 2 and the single-track switch 3 from; the 5 mentarilyclosed-becausetherelayLCS becomes positions assumed under normal; conditions oj-the energized directly in the stick. circuit .for relay system; the automatic startrelay 2-.-3AGH;ior- [LC that hasbeen described; The picking up the station associated with the control of these: ofrelay LCS opens :the pick up circuit for relay track switches remains energized;-and-thus there lACH at back contact 4231- The relay 46H is is no control cycle transmitted. underthe spe maintained energized by its stick circuit include cific condition of route establishment which-is ing back contact l3l! of relay 4L0 and front con being considered for the control of these -tracktact l3l. or relay 40H until the relay 4L0 is switches. It will thuslbe-seenythatautomatic picked up to open this'circuit at back contact start relaysiACI-I'aredropped away onlyrfora-the 13B, and thus the relays AACH and 4CH&are-.

respective stations wherein a change in the po -l l5. restoredto their-respective normally energized sition of oneor more of-the track switches is and deenergized positionsupon energization lot called for by the route beingselected. The-.ac-- theassociatedrelay ALC for initiation of'a contual initiation of the=transmission .ofcontrols trol cycle for transmission of controls-for the for these stations-having their relays AGE; track switches of crossoveril. .Theinitiation-of dropped away is not rendered effective until thezcycle upon thepicking up-of relay LGS is accomplete selection has been accomplished for all" complished in a manner fully disclosed in the track switches in the routedesignated; and until above mentioned Hailes et all patent; and this it is checked that the relays NWZ and have relay-LCS is maintained picked up until the end responded in correspondence withtheassoeiated of the'cycle because of the backcontact l2-i.-of

switch positions that have'been'selected-.-: 25. relay LV (last step relay) being maintained- Subsequent to these relays having been =conclosed until the transmissionof the control pulses ditioned for the route under consideration -ia hasbeen completed. pick up circuit is closed-for: the relay l ICH (see The energization of-relay lliC during thercons Fig; 3C) extending from including front trol cycle of: operatiomof the communication contact H (see Fig. 3B) of. relay iEXR-iront con system connects the respectivechannel wires Nos.- tact 12 of relay 4BY, front contact Til er-relay i, 2, .3, Q and 3i throughicont'acts and jumpers GRWZ; front contact- -19f0fw1615157 iR;;.wire.- 8U, seleeting'the respectivecharacters to-be trans= back contact 81 of 'relaytY iront contact BA-0t mint-ted through these respective-channels.- It is relay 3NWZ, front contacttfi of relay.. 3N,- ifmnt thus provided that the channel wires I, '2, and 3 contact!l3oirelay2NWZyiront eontactdikof: am connected through front contacts I32; 533, relay 2AN,-' wire vl lEwback contact :1 16 of relay and its respectivelyofJ-relay: fiLC; throu'gliwhe NRC; upper windingof relay] lCI-Lwvire H-'i-, and. code determiningjumpers 135; 136; and 131 so normally closed contactt l l8'of thecancelbutton to provide that the first three characters CNPB, to -l. transmitted during the. cycle are respectively Upon the pickingup-of. relay 10H; energyis- 4 (SL), (LS) and (SL). The fourth characte'roi. applied toa pick up bus 1 lil throughcfront oon-- the control code under consideration isa .s'pare' tact I20 of relay] IGH :toprovide energy for :thechannel and is not used forrcbntrol purposes, picking up of all switch. control-.stationI-startre-c and thus therelayLS is picked forth'is channel lays CH that have-had their :circuits---conditioned through front contact. 138 of relay 411C. The for energization by the dropping away of the fifth character transmittediduring:control cycle associated-normally energizedrelayAGI-Ii Thus," i-detcrziiines the position to*'which the track" under the specific assumed conditionstherelay switches" of crossover i are'tovberactuated' as QAGH-is dropped awaylat this time so that'relay determined by the rclays' lNWZ and lRWZ'; and 4(3His picked up by: energyapplied to this pick-1 under the assumed conditions .Whe're'the. relay up bus. H9 througnback contact 41% ot relay-q RWZ is picked up and the: relay GNWZ is'de'i- AACH: energized, the character transmitte'd' .is a (SE) Relay 46H when pickedup' closes: apick up character as selected by'frcnt contact I39 0f relay circuit for'the relay 4L0, such circuitincluding: ARWZ. In'accord'ance with the modeof opera back contactsl2l, I22; and 923 of relaysl-SB,- .CF tion o'f'the code communication sy'ste'mas set an -L p iv 1Y, r n c lik f r l y forth' in the above mentioned Hailes et al. patent,

40H, lower w d g of relay-ALC cancel'busrlllrthe selective en'ergization of the relays LS and and normally closed contact H3 of the cancel:' SLthrough code selecting circuits as has been button CNPB. When relay 4L6. is .picked' uri described provides in accordance with-the closure under these conditio s i s e r e of their front contacts :40 and" m respectively p until e end of the Control Cycle that ,for' the selective transmission of the respective s initiated by Stick circuit whichiishfgizd code characterslLS) and (BL). thatha've been through back contacts 125, I26; and I M- or relays:-- Selected for transmission SB, C and LV respectively connected in multiple; 53 ;552 1553; Contact nsoflelay" Wale-has n completed, the relay- LV ispicked ton CNPB." Relay LCS' is thus picked up at the-i energization of this stick circuit soc-that: V maintained picked up throuehout'the cyclecand i i may i the picking up :otthisv relay Opens the pickup. gizes the relay LCS, by the opening of back eoncircuit.ior=tharelaysl-Gatback Cont ct nan-ta mt Thus the relays 4L9 and ms are When the transmission of..the switchcontrol lahofii'thlbuti 11p,- and the picking up of that-relay prior to the itis dropping away of the relays SB and '6 opens the revent t0 cy l f p r ti n during a'clear out period at tlie'end or the cycle When pick 'upener'gy is applied-to the. relay of" operation, and the dropping away of the relay 4L0, prior to the picking upor'reiay LCSZa pick SB- at the end or the clearing out period condi-- up;yeircuit..isic1 sed for Ithe lowerjindihg joii t trons: circuit 'whi'cbyiahothei'iilayfizb can": 

